// #ifdef local
#pragma GCC optimize(1)
#pragma GCC optimize(2)
#pragma GCC optimize(3)
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
// #endif
//  #pragma comment(linker, "/STACK:102400000,102400000")

#include <algorithm>
#include <bitset>
#include <cassert>
#include <cctype>
#include <chrono>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>

#ifndef local
#define endl '\n'
#endif

#define pb emplace_back
#define fi first
#define se second
#define rep(i, l, r) for (long long i = l; i <= r; i++)
#define IOS ios::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define mem(a, x) memset(a, x, sizeof(a))
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double db;
// typedef double db;
typedef pair<ll, ll> P;
typedef pair<P, ll> PP;
typedef pair<double, double> PD;
const double pi = acos(-1);
typedef __int128_t int128;
const db eps = 1e-9;
std::mt19937_64 rng(time(0));
ll my_random(ll l, ll r)
{
	uniform_int_distribution<int> range(l, r);
	return range(rng);
}
void __()
{
#ifdef local
	system("pause");
#endif
}
ll qp(ll a, ll b, ll mod)
{
	ll ans = 1;
	while (b)
	{
		if (b & 1)
			ans = ans * a % mod;
		a = a * a % mod;
		b >>= 1;
	}
	return ans;
}
const int INF = 0x3f3f3f3f;
const int maxn = 1e5 + 10;
const int maxm = 1e6 + 10;
string s[210];
int main()
{
	IOS;
	// freopen("a.in", "r", stdin);
	// freopen("a.out", "w", stdout);
	int n, m, k;
	cin >> n >> m >> k;
	map<string, int> mp;
	for (int i = 1; i <= n; i++)
	{
		cin >> s[i];
		for (int j = 0; j < m; j++)
		{
			mp[s[i].substr(j * k, k)]++;
		}
	}
	string ans;
	for (auto x : mp)
	{
		// cout << x.fi << " " << x.se << endl;
		if (x.se == 1)
			ans = x.fi;
	}

	// cout << ans << endl;
	for (int i = 1; i <= n; i++)
	{
		for (int j = 0; j < m; j++)
		{
			if (s[i].substr(j * k, k) == ans)
			{
				cout << i << " " << j + 1 << endl;
				__();
				return 0;
			}
		}
	}

	__();
	return 0;
}